title: Influence of LRH on gonadotrophin and testosterone levels in the foetal male rat.
abstract: Gonadotrophin and testosterone levels were measured in male foetal rats at the 21st day of gestation 30 min following administration of LRH. The releasing hormone was administered by 3 different routes: subcutaneously as a single injection to the pregnant rat; subcutaneously as 12 times repeated injection to the pregnant rat from 16th-21st day of gestation; direct injection into the amniotic cavity. Three different doses of 1, 5, and 10 microgram/kg were used. The single administration to the dam was without effect. Repeated doses resulted in a significant dose-dependent elevation of mean foetal LH: 163 ng/ml in the control animals and 133,256, and 363 ng/ml in the 1, 5, and 10 microgram/kg LRH group resp. Intra animal injections significantly increased FSH and LH levels, but only those of FSH were clearly dose-dependent. A mean of 390 ng/ml in the control group was observed, with 1 microgram/kg LRH FSH was elevated to 723 ng/ml, at 5 microgram/kg to 928 and at 10 microgram/kg to 1017 ng/ml. Testosterone levels were not significantly altered. Our results demonstrate that the pituitary of foetal rats is able to respond to LRH in the same manner as adult animals.
mesh_terms: D000818:Animals; D005260:Female; D005312:Fetal Blood / Q000032:analysis*; D005333:Fetus; D005640:Follicle Stimulating Hormone / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D011247:Pregnancy; D051381:Rats; D013739:Testosterone / Q000097:blood*
chemical_list: D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone